Metabolic Response of Chardonnay Grape Marc in Hyperlipidemic, Overweight and Obese Adult Men and Women
- Lee, Fanny
- Advisor(s): Keim, Nancy L.
Atherosclerosis cardiovascular disease (ASCVD) is a complex, multifaceted condition that affects millions of adults; modifiable risk factors include weight, cholesterol, blood pressure and glucose control. Flavan-3-ols from cocoa and grapes and resveratrol from wine have been studied as strategies to improve vascular function, cholesterol, and glucose concentrations. Initiatives through the United States Department of Agriculture (USDA) have encouraged valorization of agricultural waste streams, such as wine production. The present study used Chardonnay grape marc (skins and seeds, also called pomace) blends, which builds upon the valorization efforts of the USDA yet also on the literature that phenolics provide a healthful addition to human diets. The purpose of this research was to determine whether results from previous animal trials that supplemented Chardonnay seed flour or Chardonnay seed extract, which identified improved cholesterol concentrations and glucose regulation, would translate to overweight, hyperlipidemic adult men and women. In addition, we were also interested in whether Chardonnay marc blends would impact gut hormones related to appetite control. The present study was a 16-week, randomized, double blinded crossover trial. We collected data from a total of 27 participants, where 24 individuals completed the full trial, and 3 individuals withdrew from the study. Participants were recruited based on criteria of having elevated lipids but non-medicated. This study supplemented proprietary formulations of a high Chardonnay seed extract and Chardonnay marc blend (HE), high Chardonnay marc and Chardonnay seed extract blend (HM) and a non-grape comparator of microcrystalline cellulose (MCC) for 3-weeks per intervention. Our first aim evaluated the impact of Chardonnay blends on ASCVD risk factors, specifically lipids and endothelial function. We concluded that there were no differences in fasting clinical lipid parameters of total cholesterol, low-density lipoprotein cholesterol (LDL-C), non-high density lipoprotein cholesterol (non-HDL-C) and triglycerides (TG). HDL-C was significantly lower following the HE intervention compared to both MCC and HM. Further NMR lipoprotein profiling revealed that the number of large HDL particles was significantly lower following HE compared to the MCC intervention. Postprandial triglyceride area under the curve was lower following the HM intervention compared to the HE intervention. There were no effects of the interventions on apolipoproteins AI, B, or CIII. Nor were there effects on oxidized LDL concentrations. Endothelial function, as measured by the finger plethysmography device EndoPat, was not affected by any of the interventions. The next aim investigated whether the Chardonnay blends would have an impact on glucose regulation. The results indicated that following the HM intervention, fasting glucose, and insulin decreased, in addition to indexes of insulin resistance and sensitivity compared to the MCC intervention were improved. There were no changes following the interventions in postprandial glucose or insulin response. The HM intervention also resulted in decreased concentrations of acute phase inflammation marker, serum amyloid A (SAA), compared to both MCC and HE interventions. However, this decreased SAA was not associated with the improved glycemic outcomes. The last aim explored the effects of the Chardonnay blends on gut hormones, ghrelin and peptide YY (PYY), as they related to appetite response. Here, we concluded that the HE blend decreased subjective ratings of hunger compared to MCC, despite the lack of changes in ghrelin concentrations, which signals hunger. In addition, following the HM supplementation, the concentrations of the hormone PYY, which signals satiation, was significantly higher compared to HE. No other subjective ratings of appetite were significant. This trial was the first to evaluate Chardonnay marc blends in numerous aspects of metabolism surrounding ASCVD. Phenolic compounds may not be the whole story when it comes to grape products and health potential. Our results indicate that the high marc blend has the potential to impact several risk factors and may be part of an overall strategy to reduce ASCVD risk. However, these are early results that should continue to be evaluated in future studies.